Multi-purpose injection and production well system

ABSTRACT

A method and apparatus for simultaneously producing fluid from one or more zones of an oil or gas well, while injecting fluid into one or more other zones of the well, and for converting a depleted production zone into an injection zone, by remotely shifting sleeves in the apparatus to selectively align inlet and outlet ports with production and injection flow paths, respectively. A production string is provided within a completion string; the completion string has inlet and outlet ports to the well bore. One or more production sleeves have production conduits which can be selectively aligned with inlet ports by shifting the production sleeves. One or more injection sleeves have injection conduits which can be selectively aligned with outlet ports by shifting the injection sleeves.

CROSS REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is in the field of equipment used in the production offluids from, and injection of fluids into, oil and gas wells havingmultiple zones.

2. Background Art

Many oil or gas wells extend through multiple formations, resulting inthe establishment of multiple zones at different depths in the well. Itmay be desirable to produce formation fluids such as gas or oil fromdifferent zones at different times, and to inject fluids such as waterinto different zones at different times, for the purpose of ultimatelyobtaining the maximum production from the well. Further, it may bedesirable to produce formation fluids from one or more zones, whilesimultaneously injecting fluids into one or more other zones. Finally,it may be desirable to convert a particular zone from a production zoneinto an injection zone, after the zone is depleted.

Known equipment for these purposes usually requires pulling thecompletion assembly from the well, and changing or reconfiguring theequipment in the assembly, when it is desired to commence or ceaseproduction or injection in a particular zone. Further, known equipmentis generally limited to the production of fluid or the injection offluid at any given time, with simultaneous production and injection notbeing possible, or at least difficult. More specifically, knownequipment is not capable of the simultaneous production from multiplezones and injection into multiple zones.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for selectivelyinjecting into a given zone or multiple zones, or producing from a givenzone or multiple zones, without pulling the equipment from the well. Acompletion unit is positioned next to each zone of the formation, withzones being segregated by packers. An injection sleeve and a productionsleeve are provided in each completion unit. Each sleeve essentiallybridges between the completion string and the production string, whichis within the completion string. Each sleeve is shifted, such as byhydraulic, electrical, or mechanical operation, to selectively align aconduit through the sleeve with its associated port in the wall of thecompletion string. When aligned with the inlet port, the conduit in theproduction sleeve conducts formation fluid into a production fluid pathin the production string. When aligned with the outlet port, the conduitin the injection sleeve conducts injection fluid from an injection fluidpath into the formation. Regardless of sleeve position, both injectionflow and production flow can be maintained through the completion unitto other completion units above or below.

By selectively shifting the sleeves, selected zones can be isolated,produced from, or injected into, as desired. One or more lower zones canbe injected into while one or more upper zones are produced from, orvice versa. If desired, alternating zones can be even be simultaneouslyproduced from and injected into.

The novel features of this invention, as well as the invention itself,will be best understood from the attached drawings, taken along with thefollowing description, in which similar reference characters refer tosimilar parts, and in which:

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a longitudinal section of a production unit as implemented inthe present invention, with production flow from the zone isolated;

FIG. 2 is a transverse section of a production sleeve as used in theproduction unit of FIG. 1;

FIG. 3 is a longitudinal section of the production unit of FIG. 1, withproduction flow from the zone established;

FIG. 4 is a longitudinal section of an injection unit as implemented inthe present invention, with injection flow into the zone isolated;

FIG. 5 is a transverse section of an injection sleeve as used in theinjection unit of FIG. 4;

FIG. 6 is a longitudinal section of the injection unit of FIG. 4, withinjection flow into the zone established;

FIG. 7 is a longitudinal section of a completion unit, showingproduction flow from the zone established, and showing an alternativeconfiguration of the completion and production strings;

FIG. 8 is a longitudinal section of the completion unit of FIG. 7,showing production flow from the zone and injection flow into the zoneboth isolated; and

FIG. 9 is a longitudinal section of the completion unit of FIG. 7,showing injection flow into the zone established.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, a production unit 10 used as part of the presentinvention includes a completion string 12 of tubing or piping, aproduction string 14 of tubing or piping, one or more centralizing rings16, and a longitudinally shiftable production sleeve 18. This productionunit can be placed in a well bore, aligned with a selected zone of thedownhole formation. The completion string 12 shown is flush jointpiping, and the production string 14 can be flush joint piping. Othertypes of piping or tubing can also be used. The production string 14 issubstantially coaxially located within the completion string 12,centralized therein by the centralizing rings 16. An upper end 19 and alower end 21 of the production sleeve 18 are configured to slidablymount within production string fittings 23, for shifting of theproduction sleeve 18 by means of longitudinal movement relative to thecompletion string 12. It will be seen that shifting of the productionsleeve 18 could be rotational relative to the completion string 12,rather than longitudinal, if desired.

FIG. 2 shows a transverse section of the production sleeve 18. One ormore production fluid conduits 22 are arranged more or less radiallyfrom the center of the production sleeve 18 to its outer periphery. Oneor more injection fluid bypass channels 24 pass longitudinally throughthe production sleeve 18, to ensure that injection fluid can bypass theproduction sleeve from an upper annulus to a lower annulus. A productionfluid flow path 28 passes longitudinally through the production sleeve18, ensuring the production fluid from a lower zone can pass to an upperzone. The production fluid conduits 22 are also in fluid flowcommunication with the production fluid flow path 28.

FIG. 1 shows only one of the production fluid conduits 22, and only oneof the bypass channels 24. However, it can be seen that, regardless ofthe position of the production sleeve 18, an injection fluid flow pathexists through the production sleeve 18 as indicated by the arrowlabeled IF. Further, the injection fluid flow path continues throughbypass channels 26 in the centralizing rings 16. This allows injectionfluid pumped downhole in the annulus between the completion string 12and the production string 14 to flow completely through the productionunit 10 from an upper zone to a lower zone, regardless of the positionof the production sleeve 18.

It also can be seen that, regardless of the position of the productionsleeve 18, production fluid can flow through the production fluid flowpath 28 in the production sleeve 18 as indicated by the arrow labeledPF. Further, production fluid can flow through the center of thecentralizing rings 16, in the production fluid flow path 28 in theproduction string 14. This allows production fluid to flow completelythrough the production unit 10 from a lower zone to an upper zone,regardless of the position of the production sleeve 18.

Shifting of the production sleeve 18 could be accomplished by severaldifferent means, such as hydraulically, mechanically, or electrically,or a combination thereof. FIG. 1 shows one embodiment of a hydraulicshifting means, including an upper hydraulic duct 30, a lower hydraulicduct 32, and a two directional hydraulic chamber 34. A shoulder on theproduction sleeve 18 can be positioned in the hydraulic chamber 34. Whenthe upper duct 30 is pressurized, the production sleeve 18 is shifteddownwardly, or to the right in the figure. When the lower duct 32 ispressurized, the production sleeve 18 is shifted upwardly, or to theleft in the figure. A similar hydraulic assembly could be used torotationally shift the production sleeve 18, if preferred. Further, anelectrical solenoid mechanism could accomplish either longitudinal orrotational shifting, if preferred. Still further, other known shiftingmechanisms could be used to shift the production sleeve 18.

A formation fluid inlet port 20 is formed through the wall of thecompletion string 12. The production fluid conduit 22 in the productionsleeve 18 does not align with the inlet port 20, when the productionsleeve 18 is in the upper position shown in FIG. 1. This isolates theinlet port 20, preventing flow of formation fluid through the inlet port20, through the production fluid conduit 22, and into the productionfluid flow path 28. FIG. 3 illustrates that the production sleeve 18 canbe selectively shifted downwardly when desired, to align the productionfluid conduit 22 with the inlet port 20. This establishes flow offormation fluid through the inlet port 20, through the production fluidconduit 22, and into the production fluid flow path 28.

As shown in FIG. 4, an injection unit 40 used as part of the presentinvention includes the completion string 12, the production string 14,one or more centralizing rings 16, and a longitudinally shiftableinjection sleeve 42. This injection unit also can be placed in a wellbore, aligned with a selected zone of the downhole formation. As will beseen, the injection unit 40 can be associated with a production unit 10for a particular zone of the formation, to facilitate selectiveproduction from, or injection into, the zone. An upper end 43 and alower end 45 of the injection sleeve 42 are configured to slidably mountwithin production string fittings 23, for shifting of the injectionsleeve 42 by means of longitudinal movement relative to the completionstring 12. It will be seen that shifting of the injection sleeve 42could be rotational relative to the completion string 12, rather thanlongitudinal, if desired.

FIG. 5 shows a transverse section of the injection sleeve 42. One ormore injection fluid conduits 46 are arranged at several locations,connecting the upper side of the injection sleeve 42 to its outerperiphery. One or more injection fluid bypass channels 56 passlongitudinally through the injection sleeve 42, to ensure that injectionfluid can bypass the injection sleeve from an upper annulus to a lowerannulus. A production fluid flow path 28 passes longitudinally throughthe injection sleeve 42, ensuring the production fluid from a lower zonecan pass to an upper zone.

FIG. 4 shows only one of the injection fluid conduits 46, and only oneof the bypass channels 56. However, it can be seen that, regardless ofthe position of the injection sleeve 42, an injection fluid flow pathexists through the injection sleeve 42 as indicated by the arrow labeledIF. Further, the injection fluid flow path continues through bypasschannels 26 in the centralizing rings 16. This allows injection fluidpumped downhole in the annulus between the completion string 12 and theproduction string 14 to flow completely through the injection unit 40from an upper zone to a lower zone, regardless of the position of theinjection sleeve 42.

It also can be seen that, regardless of the position of the injectionsleeve 42, production fluid can flow through the production fluid flowpath 28 in the injection sleeve 42 as indicated by the arrow labeled PF.Further, production fluid can flow through the center of thecentralizing rings 16, in the production fluid flow path 28 in theproduction string 14. This allows production fluid to flow completelythrough the injection unit 40 from a lower zone to an upper zone,regardless of the position of the injection sleeve 42.

Shifting of the injection sleeve 42 could be accomplished by severaldifferent means, such as hydraulically, mechanically, or electrically,or a combination thereof. FIG. 4 shows one embodiment of a hydraulicshifting means, including an upper hydraulic duct 50, a lower hydraulicduct 52, and a two directional hydraulic chamber 54. A shoulder on theinjection sleeve 42 can be positioned in the hydraulic chamber 54. Whenthe upper duct 50 is pressurized, the injection sleeve 42 is shifteddownwardly, or to the right in the figure. When the lower duct 52 ispressurized, the injection sleeve 42 is shifted upwardly, or to the leftin the figure. A similar hydraulic assembly could be used torotationally shift the injection sleeve 42, if preferred. Further, anelectrical solenoid mechanism could accomplish either longitudinal orrotational shifting, if preferred. Still further, other known shiftingmechanisms could be used to shift the injection sleeve 42.

An injection fluid outlet port 44 is formed through the wall of thecompletion string 12. The injection fluid conduit 46 in the injectionsleeve 42 does not align with the outlet port 44, when the injectionsleeve 42 is in the upper position shown in FIG. 4. This isolates theoutlet port 44, preventing flow of injection fluid through the injectionfluid conduit 46, through the outlet port 44, and into the formation.FIG. 6 illustrates that the injection sleeve 42 can be selectivelyshifted downwardly when desired, to align the injection fluid conduit 46with the outlet port 44. This establishes flow of injection fluidthrough the injection fluid conduit 46, through the outlet port 44, andinto the formation.

FIGS. 7, 8, and 9 illustrate the pairing of a production unit 10 with aninjection unit 40 to form a completion unit, which can be placeddownhole in a well bore, aligned with a selected zone of the formation.Packers 58 can be used to isolate adjacent zones. FIGS. 7, 8, and 9 alsoillustrate a variation of the configuration of the completion string andthe production string, when it is desired to pump injection fluid intothe annulus surrounding the completion string, rather than pumpinginjection fluid into an annulus between the completion string and theproduction string, as in the embodiments shown in FIGS. 1, 3, 4, and 6.In either embodiment, however, production fluid flow and injection fluidflow can be controlled as shown in FIGS. 7, 8, and 9.

FIG. 7 shows the production sleeve 18 in its lower position, and theinjection sleeve 42 in its upper position. This establishes flow offormation fluid from the zone into the production fluid flow path 28,while preventing flow of injection fluid into the zone. FIG. 8 shows theproduction sleeve 18 in its upper position, and the injection sleeve 42in its upper position. This prevents flow of formation fluid from thezone into the production fluid flow path 28, while also preventing flowof injection fluid into the zone. FIG. 9 shows the production sleeve 18in its upper position, and the injection sleeve 42 in its lowerposition. This prevents flow of formation fluid from the zone into theproduction fluid flow path 28, while establishing flow of injectionfluid into the zone.

It can be seen that, by selective shifting of the production sleeves 18and the injection sleeves 42 in multiple zones, one or more zones canproduce formation fluid, simultaneous with the injection of fluid intoone or more other zones.

While the particular invention as herein shown and disclosed in detailis fully capable of obtaining the objects and providing the advantageshereinbefore stated, it is to be understood that this disclosure ismerely illustrative of the presently preferred embodiments of theinvention and that no limitations are intended other than as describedin the appended claims.

1. A system for injecting fluid into, and producing fluid from, multiplezones in a well bore, comprising: a tubular completion string, saidcompletion string having a production fluid inlet port and an injectionfluid outlet port; a production fluid flow path within said completionstring; an injection fluid flow path within said completion string; aproduction fluid sleeve bypass channel connecting a portion of saidinjection fluid flow path above said production fluid inlet port to aportion of said injection fluid flow path below said production fluidinlet port; an injection fluid bypass channel connecting a portion ofsaid injection fluid flow path above said injection fluid outlet port toa portion of said injection fluid flow path below said injection fluidoutlet port; a production fluid conduit, said production fluid conduitbeing adapted to shift relative to said completion string to selectivelyconduct production fluid from said production fluid inlet port to saidproduction fluid flow path; and an injection fluid conduit, saidinjection fluid conduit being adapted to shift relative to saidcompletion string to selectively conduct injection fluid from saidinjection fluid flow path to said injection fluid outlet port.
 2. Theinjection and production system recited in claim 1, wherein saidproduction fluid conduit is slidably mounted in said completion stringto selectively conduct production fluid from said production fluid inletport to said production fluid flow path, by sliding longitudinallyrelative to said completion string.
 3. The injection and productionsystem recited in claim 1, wherein said injection fluid conduit isslidably mounted in said completion string to selectively conductinjection fluid from said injection fluid flow path to said injectionfluid outlet port, by sliding longitudinally relative to said completionstring.
 4. The injection and production system recited in claim 1,further comprising: a first packer surrounding said completion stringabove said production fluid inlet port and said injection fluid outletport; and a second packer surrounding said completion string below saidproduction fluid inlet port and said injection fluid outlet port.
 5. Theinjection and production system recited in claim 1, further comprising:a plurality of said production fluid conduits; and a plurality of saidinjection fluid conduits.
 6. The injection and production system recitedin claim 5, wherein each of said production fluid conduits is associatedwith an adjacent said injection fluid conduit to comprise an associatedpair of fluid conduits, and further comprising a packer surrounding saidcompletion string between adjacent said associated pairs of saidproduction and injection fluid conduits.
 7. The injection and productionsystem recited in claim 1, further comprising a tubular productionstring within said completion string, wherein: said production fluidflow path passes through said production string; and said productionfluid conduit is adapted to shift relative to said completion string toselectively conduct production fluid from said production fluid inletport to said production string.
 8. The injection and production systemrecited in claim 1, further comprising a tubular production stringwithin said completion string, wherein: said injection fluid flow pathpasses through a space between said production string and saidcompletion string; and said injection fluid conduit is adapted to shiftrelative to said completion string to selectively conduct injectionfluid from said space between said production and completion strings tosaid injection fluid outlet port.
 9. The injection and production systemrecited in claim 1, further comprising a tubular production stringwithin said completion string, wherein: said injection fluid flow pathincludes a space between said production string and said completionstring; said production fluid conduit passes through said space betweensaid production string and said completion string; and said productionfluid sleeve bypass channel bypasses said production fluid conduit froma portion of said space above said production fluid conduit to a portionof said space below said production fluid conduit.
 10. The injection andproduction system recited in claim 1, further comprising a tubularproduction string within said completion string, wherein: said injectionfluid flow path includes a space between said production string and saidcompletion string; said injection fluid conduit passes through saidspace between said production string and said completion string; andsaid injection fluid bypass channel bypasses said injection fluidconduit from a portion of said space above said injection fluid conduitto a portion of said space below said injection fluid conduit.
 11. Theinjection and production system recited in claim 1, wherein saidproduction fluid conduit is adapted for shifting under remote control toselectively conduct production fluid from said production fluid inletport to said production fluid flow path.
 12. The injection andproduction system recited in claim 11, further comprising a hydraulicactuator adapted to remotely shift said production fluid conduit. 13.The injection and production system recited in claim 1, wherein saidinjection fluid conduit is adapted for shifting under remote control toselectively conduct injection fluid from said injection fluid flow pathto said injection fluid outlet port.
 14. The injection and productionsystem recited in claim 13, further comprising a hydraulic actuatoradapted to remotely shift said injection fluid conduit.
 15. A system forinjecting fluid into, and producing fluid from, multiple zones in a wellbore, comprising: a tubular completion string, said completion stringhaving a production fluid inlet port and an injection fluid outlet port;a production fluid flow path within said completion string; an injectionfluid flow path within said completion string; a production sleevemounted within said completion string; an injection sleeve mountedwithin said completion string; a production sleeve bypass channelconnecting a portion of said injection fluid flow path above saidproduction sleeve to a portion of said injection fluid flow path belowsaid production sleeve; an injection sleeve bypass channel connecting aportion of said injection fluid flow path above said injection sleeve toa portion of said injection fluid flow path below said injection sleeve;a production fluid conduit in said production sleeve, said productionsleeve being adapted to shift relative to said completion string toselectively conduct production fluid from said production fluid inletport to said production fluid flow path via said production fluidconduit; and an injection fluid conduit in said injection sleeve, saidinjection sleeve being adapted to shift relative to said completionstring to selectively conduct injection fluid from said injection fluidflow path to said injection fluid outlet port via said injection fluidconduit.
 16. The injection and production system recited in claim 15,wherein said production sleeve is slidably mounted in said completionstring to selectively conduct production fluid from said productionfluid inlet port to said production fluid flow path, via said productionfluid conduit, by sliding longitudinally relative to said completionstring.
 17. The injection and production system recited in claim 15,wherein said injection sleeve is slidably mounted in said completionstring to selectively conduct injection fluid from said injection fluidflow path to said injection fluid outlet port, via said injection fluidconduit, by sliding longitudinally relative to said completion string.18. The injection and production system recited in claim 15, furthercomprising: a first packer surrounding said completion string above saidproduction and injection sleeves; and a second packer surrounding saidcompletion string below said production and injection sleeves.
 19. Theinjection and production system recited in claim 15, further comprising:a plurality of said production sleeves; and a plurality of saidinjection sleeves.
 20. The injection and production system recited inclaim 19, wherein each of said production sleeves is associated with anadjacent said injection sleeve to comprise an associated pair ofsleeves, and further comprising a packer surrounding said completionstring between adjacent said associated pairs of said production andinjection sleeves.
 21. The injection and production system recited inclaim 15, further comprising a tubular production string within saidcompletion string, wherein: said production fluid flow path passesthrough said production string; and said production sleeve is adapted toshift relative to said completion string to selectively conductproduction fluid from said production fluid inlet port to saidproduction string, via said production fluid conduit.
 22. The injectionand production system recited in claim 15, further comprising a tubularproduction string within said completion string, wherein: said injectionfluid flow path passes through a space between said production stringand said completion string; and said injection sleeve is adapted toshift relative to said completion string to selectively conductinjection fluid from said space between said production and completionstrings to said injection fluid outlet port, via said injection fluidconduit.
 23. The injection and production system recited in claim 15,further comprising a tubular production string within said completionstring, wherein: said injection fluid flow path includes a space betweensaid production string and said completion string; said productionsleeve bridges said space between said production string and saidcompletion string; and said production sleeve bypass channel passesthrough said production sleeve from a portion of said space above saidproduction sleeve to a portion of said space below said productionsleeve.
 24. The injection and production system recited in claim 15,further comprising a tubular production string within said completionstring, wherein: said injection fluid flow path includes a space betweensaid production string and said completion string; said injection sleevebridges said space between said production string and said completionstring; and said injection sleeve bypass channel passes through saidinjection sleeve from a portion of said space above said injectionsleeve to a portion of said space below said injection sleeve.
 25. Theinjection and production system recited in claim 15, wherein saidproduction sleeve is adapted for shifting under remote control toselectively conduct production fluid from said production fluid inletport to said production fluid flow path.
 26. The injection andproduction system recited in claim 25, further comprising a hydraulicactuator adapted to remotely shift said production sleeve.
 27. Theinjection and production system recited in claim 15, wherein saidinjection sleeve is adapted for shifting under remote control toselectively conduct injection fluid from said injection fluid flow pathto said injection fluid outlet port.
 28. The injection and productionsystem recited in claim 27, further comprising a hydraulic actuatoradapted to remotely shift said injection sleeve.
 29. A system forinjecting into and producing from multiple zones in a well bore,comprising: a tubular completion string, said completion string having aproduction fluid inlet port and an injection fluid outlet port; atubular production string within said completion string; a productionsleeve mounted on said production string; an injection sleeve mountedwithin said completion string; a plurality of bypass channels throughsaid production sleeve and said injection sleeve, in fluid communicationwith a space between said production string and said completion string;a production fluid conduit in said production sleeve, said productionsleeve being adapted to shift relative to said completion string toselectively conduct production fluid from said production fluid inletport to said production string, via said production fluid conduit; andan injection fluid conduit in said injection sleeve, said injectionsleeve being adapted to shift relative to said completion string toselectively conduct injection fluid from said space between saidproduction string and said completion string, to said injection fluidoutlet port, via said injection fluid conduit.
 30. A method forproducing fluid from a production zone of a well bore and injectingfluid into an injection zone of a well bore, said method comprising:providing a tubular completion string, said completion string having aproduction fluid conduit and an injection fluid conduit therein, saidcompletion string having an inlet port and an outlet port through a wallthereof; aligning said inlet port with a production zone of a well bore;aligning said outlet port with an injection zone of said well bore;pumping injection fluid into an injection fluid flow path within saidcompletion string; selectively shifting said injection fluid conduit andsaid production fluid conduit relative to said completion string toplace said injection fluid flow path in fluid flow communication withsaid outlet port, and to place said inlet port in fluid flowcommunication with a production fluid flow path in said completionstring; and injecting fluid through said outlet port into said injectionzone and producing fluid through said inlet port from said productionzone.
 31. The method recited in claim 30, further comprising: providinga plurality of production fluid conduits and a plurality of inlet portsin said completion string; aligning said plurality of inlet ports with aplurality of production zones of a well bore; selectively shifting saidplurality of production fluid conduits relative to said completionstring to place at least one said inlet port in fluid flow communicationwith a production fluid flow path in said completion string; andinjecting fluid through said outlet port into said injection zone andproducing fluid through said at least one inlet port from at least onesaid production zone.
 32. The method recited in claim 30, furthercomprising: providing a plurality of injection fluid conduits and aplurality of outlet ports in said completion string; aligning saidplurality of outlet ports with a plurality of injection zones of saidwell bore; selectively shifting said plurality of injection fluidconduits relative to said completion string to place said injectionfluid flow path in fluid flow communication with at least one saidoutlet port; and injecting fluid through said at least one outlet portinto at least one said injection zone and producing fluid through saidinlet port from said production zone.
 33. The method recited in claim30, further comprising: providing a plurality of production fluidconduits, a plurality of injection fluid conduits, a plurality of inletports, and a plurality of outlet ports in said completion string;aligning said plurality of inlet ports with a plurality of productionzones of a well bore; aligning said plurality of outlet ports with aplurality of injection zones of said well bore; selectively shiftingsaid plurality of injection fluid conduits and said plurality ofproduction fluid conduits relative to said completion string to placesaid injection fluid flow path in fluid flow communication with saidplurality of outlet ports, and to place said plurality of inlet ports influid flow communication with a production fluid flow path in saidcompletion string; and injecting fluid through said plurality of outletports into said plurality of injection zones and producing fluid throughsaid plurality of inlet ports from said plurality of production zones.34. A method for producing fluid from a production zone of a well boreand injecting fluid into an injection zone of a well bore, said methodcomprising: providing a tubular completion string, said completionstring having a production sleeve and an injection sleeve therein, saidcompletion string having an inlet port and an outlet port through a wallthereof; aligning said inlet port with a production zone of a well bore;aligning said outlet port with an injection zone of said well bore;pumping injection fluid into an injection fluid flow path within saidcompletion string; selectively shifting said injection sleeve relativeto said completion string to place said injection fluid flow path influid flow communication with said outlet port; selectively shiftingsaid production sleeve relative to said completion string to place saidinlet port in fluid flow communication with a production fluid flow pathin said completion string; and injecting fluid through said outlet portinto said injection zone and producing fluid through said inlet portfrom said production zone.
 35. The method recited in claim 34, furthercomprising: providing a plurality of production sleeves and a pluralityof inlet ports in said completion string; aligning said plurality ofinlet ports with a plurality of production zones of a well bore;selectively shifting said plurality of production sleeves relative tosaid completion string to place at least one said inlet port in fluidflow communication with a production fluid flow path in said completionstring; and injecting fluid through said outlet port into said injectionzone and producing fluid through said at least one inlet port from atleast one said production zone.
 36. The method recited in claim 34,further comprising: providing a plurality of injection sleeves and aplurality of outlet ports in said completion string; aligning saidplurality of outlet ports with a plurality of injection zones of saidwell bore; selectively shifting said plurality of injection sleevesrelative to said completion string to place said injection fluid flowpath in fluid flow communication with at least one said outlet port; andinjecting fluid through said at least one outlet port into at least onesaid injection zone and producing fluid through said inlet port fromsaid production zone.
 37. The method recited in claim 34, furthercomprising: providing a plurality of production sleeves, a plurality ofinjection sleeves, a plurality of inlet ports, and a plurality of outletports in said completion string; aligning said plurality of inlet portswith a plurality of production zones of a well bore; aligning saidplurality of outlet ports with a plurality of injection zones of saidwell bore; selectively shifting said plurality of injection sleevesrelative to said completion string to place said injection fluid flowpath in fluid flow communication with said plurality of outlet ports;selectively shifting said plurality of production sleeves relative tosaid completion string to place said plurality of inlet ports in fluidflow communication with a production fluid flow path in said completionstring; and injecting fluid through said plurality of outlet ports intosaid plurality of injection zones and producing fluid through saidplurality of inlet ports from said plurality of production zones.
 38. Asystem for injecting fluid into, and producing fluid from, multiplezones in a wellbore, comprising: a tubular completion string; aproduction fluid flow path within said completion string adapted to bein selective communication with a plurality of production zones; aninjection fluid flow path within said completion string adapted to be inselective communication with a plurality of injection zones; a flowcontrol device comprising: a production sleeve member that is moveablebetween an open position, wherein fluid communication is permittedbetween a production zone and a production fluid flow path, and a closedposition, wherein fluid communication between the production zone andthe production fluid flow path is blocked; and an injection sleevemember that is moveable between an open position, wherein fluidcommunication is permitted between an injection fluid flow path and aninjection zone, and a closed position, wherein fluid communicationbetween the injection fluid flow path and the injection zone is blocked.39. The system of claim 38 wherein the production and injection sleevemembers are moveable between their open and closed positions by shiftingthe sleeve members axially with respect to the completion string. 40.The system of claim 39 whereby the sleeves are shifted hydraulically.41. The system of claim 38 wherein the production fluid flow path islocated coaxially within the injection fluid flow path.
 42. The systemof claim 38 wherein the completion string is constructed of flush jointtubing to provide a substantially uniform outer diameter.
 43. A methodof producing fluid from and injecting fluid into a wellbore, comprisingthe steps of: disposing a completion string into the wellbore, thecompletion string having a production fluid flow path and an injectionfluid flowpath defined therein; providing selective fluid communicationbetween the production fluid flowpath and the surrounding wellbore toselectively permit production fluid to enter the production fluidflowpath from the wellbore; and providing selective communicationbetween the injection fluid flowpath and the surrounding wellbore toselectively permit injection fluid to pass into the wellbore from theinjection fluid flowpath by shifting a shiftable sleeve from an openposition to a closed position and from a closed position to an openposition to selectively open and close an injection fluid port withinthe injection fluid flowpath.
 44. The method of claim 43 whereinselective fluid communication between the production fluid flow path andthe wellbore is provided by actuating a flow control device that ismoveable between a closed position, wherein flow is blocked, and an openposition, wherein flow is permitted.
 45. The method of claim 43 whereinproduction fluid is selectively drawn into the production fluid flowpathfrom a first zone within the wellbore, and injection fluid isselectively injected into a second zone within the wellbore.